This invention relates generally to washing machines, and more particularly, to a lid safety switch for a washing machine.
Washing machines typically include a cabinet that houses an outer tub for containing wash and rinse water, a perforated clothes basket within the tub, and an agitator within the basket. A drive and motor assembly is mounted underneath the stationary outer tub to rotate the basket and the agitator relative to one another. The washing machine performs a number of cycles to complete a wash operation including a wash cycle and one or more rinse and spin cycles. See, for example, U.S. Pat. No. 6,029,298.
As is well known, a typical top-loading washing machine has a lid with a safety switch coupled thereto that is connected in series with the motor to prevent the motor from being energized when the lid is open. The lid switch provides an interlock safety feature wherein access to the clothes basket is prevented during the agitation cycle, and more importantly, during the spin cycle of the wash operation to prevent injury to the user.
In at least some known washing machines, the lid switch is mounted to a bracket that is positioned underneath the top cover of the cabinet. The lid switch has an operating lever that biases the switch in an open position wherein the switch does not pass an electrical current so that the motor is de-energized, or rendered inoperable. The operating lever is positioned proximate an hole in the cover that provides access to the operating lever. The lid has a prong that extends downwardly and is aligned with the access hole. When the lid is in an open position, or when the lid has been moved a predetermined distance from a closed position, the prong does not engage the operating lever so that the lid switch remains in the open position and does not allow the motor to be energized. When the lid is in the closed position, the prong extends into the access hole and engages the operating lever to place the lid switch in a closed position wherein the switch passes an electrical current, thereby allowing energization, and thus, operation of the motor.
Though effective, the design also has shortcomings. For instance, the lid switch can rather easily be overridden by the insertion of small objects such as a screwdriver blade, or a finger of a child. These events can result in unsafe operation of the washer by allowing the drum to spin or the agitator to oscillate while the lid is open.